The mobile viewers include, for example, car navigation systems, in-vehicle television receivers, mobile terminals, and cell phones. The mobile viewers may be watched by drivers of vehicles, steerers of ships, or pilots of airplanes, etc. For example, a driver may get various kinds of information such as a route to a destination, a traffic situation on the route, and terrestrial broadcasting, in the vehicle.
The mobile viewers may be connected to the Internet via a cell phone for example, to display view data generated in accordance with a structured document downloaded through the Internet and analyzed by using a web browser. The mobile viewers may further display view data including a still picture or a motion picture generated in accordance with an information resource (hereinafter also referred to as “browsing data”) such as another structured document, a still picture file, and a motion picture file, downloaded from a site (referred to as a linked site) indicated by link data included in the previously received structured document (see Japanese Laid-Open Patent No. 9-166450, for example).
However, the driver needs to confirm the safety around the vehicle and may not keep his eyes on the screen during driving. Thus, watching and operating the mobile viewers increase driver's burden. Because of this, the Japan Automobile Manufacturers Association has defined screen images that are not preferable to be displayed in a moving vehicle in “Guideline for Image Display Apparatus” (hereinafter referred to as “JAMA guideline”.